Hydrometric vane with Woltmann sail wheel for fluid with frequently changing pressures

摘要

The hydrometric vane involves an impeller wheel which is arranged between hubs upstream and downstream of impeller via a shaft (8). The ends of the shaft enter respectively a chamber (11,12) formed in the hubs (1,2), thus forming an annular gap (13,14). The bearings thus act as pressure impact dampers, in that when an axial pressure impact acts on the impeller, an over pressure is formed in the chamber downstream of the impact, which is slowly dissipated due to the fluid flowing out of the chamber via the gap.